Ken Lipper — the Renaissance man who’s been a Hollywood screenwriter and was Ed Koch’s deputy mayor for finance and economic development — had jurors in stitches at Manhattan Supreme Court this week. Spies say Lipper was in the jury pool for a case involving a drug deal and during the voir dire revealed he had a Harvard Law degree, was deputy mayor and was a writer. When judge Renee White wondered what Lipper’s written, he replied, “ ‘City Hall’ with Robert De Niro.” And what was it about? “A corrupt judge,” Lipper replied to laughs from fellow potential jurors. When Lipper was asked if he had friends in law enforcement, he said he regularly meets with Manhattan DA Cyrus R. Vance Jr. for lunch, a spy said. Lipper added his relationship with Vance wouldn’t be negatively impacted if he acquitted a defendant in a case. But he was not picked for the jury. “He was very friendly and down to earth,” said a witness. Lipper was also a technical adviser on Oliver Stone’s “Wall Street” and wrote a novelization of the movie.